Rational design of superaerophobic array electrode synergy enhanced by wettability engineering and doping engineering for HER catalytic performance

Abstract

This article elucidates the synthesis of NiMoO4-based catalysts with different arrays and crystal structures, including nanowires (nw), nanoplates (ns), and nanocolumns (nc). Subsequently, a high-temperature phosphorization method was employed to generate the corresponding P-NiMoO4 catalysts. The study investigates the structural evolution of the catalysts and changes in the active species under operational conditions. Concurrently, density functional theory (DFT) calculations provide a more in-depth description of the HER reaction mechanism, considering d-band centers and adsorption energies. Experimental results demonstrate that phosphorized NiMoO4 with a nanowire array structure and crystal structures of NiMoO4 and MoO3 exhibit the optimal HER performance, displaying superhydrophilic and underwater superaerophobic behaviors. The hydrophilic contact angle is 0°, and the aerophobic contact angle is 156.8° This array electrode achieves a current density of 10 mA·cm−2 at an overpotential as low as 73.97 mV. The experiments indicate that through doping and morphology control engineering, catalytic performance can be further synergistically enhanced, providing a new perspective for preparing HER catalytic electrodes with potential applications.